Known as the Atheist Street Pirates, the group formed in 2021 as a subset of the LA-based Atheists United, a nonprofit that’s been in the city for 40 years and that seeks to “empower people to express secular values and promote separation of government and religion.” The street pirates’ goal is to clear city streets of religious propaganda.
Logically, it is up to believers in god(s) to make a positive case for belief in their god(s) to the exclusion of all others. That typically is a tough hurdle, which is why so many defenders of particular god(s) prefer to restrict their argument to their faith vs none at all atheism, rather than a far slipperier comparative religion defense.
I’m writing this a few weeks after the original discussion of the question took place. I'm also writing this soon after the death of Pete Seeger, who was an atheist the last time I heard him talk live, about 25 years ago.
It's hard to be considered part of something when the whole point of your belief lacks the major criteria that everyone else in the category possesses.